X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=family_tree_of_functional_programming_languages.mdwn;h=f13929daca8ecba8a584cc90c13a8f34d5b90476;hp=7e018aa588067bfd01f1693f7e55e59c022c8385;hb=399f4aa37f2dbcd96af05a841056c2da33e38ca1;hpb=118f60c5fb8747096249fae8bb864c0427503da7

diff --git a/family_tree_of_functional_programming_languages.mdwn b/family_tree_of_functional_programming_languages.mdwn
index 7e018aa5..f13929da 100644
--- a/family_tree_of_functional_programming_languages.mdwn
+++ b/family_tree_of_functional_programming_languages.mdwn
@@ -74,7 +74,7 @@ like follows:
 
 This just says explicitly that foo takes an argument x of type int, an argument
 y of type float, and returns a pair of type int\*float (that is, a pair whose
-first member is if type int and whose second member is of type float).
+first member is of type int and whose second member is of type float).
 
 Type inference allows programmers to enjoy the benefits of strict compile-time
 type-checking, which as we said, helps eliminate a large class of errors at a
@@ -87,37 +87,37 @@ gets everything sorted out.)
 
 Though as we said dynamically-typed languages have become popular, programmers
 who get used to modern statically-typed languages find them productive.
-Sometimes they become zealots for working this way instead; at any case, they
+Sometimes they become zealots for working this way instead; in any case, they
 say that the popular dim opinion of static typing is based on out-of-date
 experiences of older languages like C and Java.
 
 Most functional programming languages these days are statically typed.
 
-We can further divide these languages based on whether they use *lazy* or
-*strict/eager* evaluation. We'll discuss the difference between these during
+We can further divide these languages based on whether they use lazy or
+strict/eager evaluation. We'll discuss the difference between these during
 the seminar.
 
-Most programming languages, functional or not, use strict/eager evaluation. For
+Most programming languages, functional or not, use **strict/eager evaluation**. For
 instance, languages of the ML family are all statically-typed functional
 languages with strict/eager evaluation. These include [[!wikipedia SML]] and
 [[!wikipedia Caml]] and [[!wikipedia Nemerle]]. Other statically-typed
-functional languages with strict/eager semantics are [[!wikipedia Scala]] and
+functional languages with strict/eager evaluation are [[!wikipedia Scala]] and
 [[!wikipedia Coq]]. Like Scheme, many of these languages permit *imperatival*
 as well as functional coding; but they are regarded as functional programming
 languages because they are so hospitable to functional programming, and give it
 a central place in their design.
 
 A few languages such as [[!wikipedia Miranda]] and [[!wikipedia Haskell]] are
-statically-typed languages that instead mostly use lazy evaluation. However,
+statically-typed languages that instead mostly use **lazy evaluation**. However,
 it'd be more strictly accurate to say Haskell is lazy *by default*. You can
 also make Haskell evaluate some expressions strictly/eagerly; you just have to
-be ask for that explicitly. (I don't know about Miranda.) Languages like OCaml
+ask for that explicitly. (I don't know about Miranda.) Languages like OCaml
 are the reverse: they're strict/eager by default, but you can get lazy
 evaluation where it's needed, you just have to ask for it explicitly.
 
 Unlike OCaml, Haskell is much more extreme about being non-imperatival. Though
 it's possible to write imperative code in Haskell, too; one just has to
-encapsulate it in a ST or IO *monad*. We'll be discussing in the seminar how
+encapsulate it in an "ST" or "IO" *monad*. We'll be discussing in the seminar how
 monads can be used to create purely functional representations of imperatival
 algorithms. (You can do the same in languages like Scheme and OCaml, too.
 What's different is that in Haskell monads are the *only* way to deal with
@@ -126,4 +126,9 @@ imperatival code.)
 We'll talk much more about monads, lazy vs strict evaluation, and functional vs
 imperatival code as we proceed.
 
+We won't much discuss static vs dynamic typing; this has to do with lower-level
+implementation details than we'll be concerned with. However, you'll encounter
+the difference in practice as you work with Scheme and OCaml, respectively; and
+you'll see it referred to as you read around. So it's good for you to
+have placed it in your mental map.